Mozilla's upstart open source web browser Firefox heads for a big milestone with the release of Firefox 2.0. We put the beta through its paces to see what changes are in store.

On the surface, Firefox 2.0 looks very much like earlier versions, with most improvements happening behind the scenes. For example, 2.0 introduces a built-in spell-checker for web forms. That's a boon for forum posters and online e-mail users.

An anti-phishing filter alerts users to sites that may be scams by comparing them with a blacklist of phishing sites. A session restore function lets users recover their pages and tabs after a crash. Firefox 2.0 scores well for its friendly interface, fast page load times, and improved tabbed browsing and search engine management. There are also a host of security improvements and bug fixes. Firefox fans will appreciate the subtle but extremely functional upgrades.